<template>
	<view class="u-wrap">
		<!-- 将左右列表联动 -->
		<view class="u-menu-wrap">
			<scroll-view
				scroll-y
				scroll-with-animation
				class="u-tab-view menu-scroll-view"
				:scroll-top="scrollTop"
				:scroll-into-view="itemId"
			>
				<view
					v-for="(item, index) in tabbar"
					:key="index"
					class="u-tab-item"
					:class="[current == index ? 'u-tab-item-active' : '']"
					@tap.stop="swichMenu(index)"
				>
					<text class="u-line-1">{{ item.name }}</text>
				</view>
			</scroll-view>
			<scroll-view
				:scroll-top="scrollRightTop"
				scroll-y
				scroll-with-animation
				class="right-box"
				@scroll="rightScroll"
			>
				<view class="page-view">
					<view class="class-item" :id="'item' + index" v-for="(item, index) in tabbar" :key="index">
						<view class="item-title">
							<text>{{ item.name }}</text>
						</view>
						<view class="myCardBox" v-for="(item1, index1) in item.foods" :key="index1"  style="margin-bottom: 80rpx;">
							<u-row :gutter="16">
								<u-col :span="4">
									<u-image :src="item1.image" width="100%" height="100rpx"></u-image>
								</u-col>
								<u-col :span="8">
									<view style="font-weight: bold;text-align: center;" class="u-line-1">{{ item1.name }}</view>
									<view class="u-line-2" style="margin-top: 4rpx;">{{ item1.detail }}</view>
									<view class="myflexRow" style="margin-top: 4rpx;">
										<view>好评率:{{ item1.favorRate }}%</view>
										<view style="color: #DD6161;margin-left: 16rpx;">
											月销量:{{ item1.saleQuantity }}
										</view>
									</view>

									<view
										style="display: flex;display: -webkit-flex; flex-direction: row; justify-content: space-between;align-items: center;"
									>
										<view>价格:{{ item1.price }}</view>
										<view class="myCartNumber">
											<u-icon name="minus" color="#81a3ff" style="border: 2rpx solid #81a3ff;border-radius: 50% ; "
											@click="minusClick(item1)" v-if="item1.minusShow"></u-icon>
											<view style="margin: 16rpx;" >{{item1.num}}</view>
											<u-icon name="plus"  color="#ffffff"
											 style="border-radius: 50% ;background-color: #81a3ff;padding: 2rpx;"
											@click="plusClick(item1)"></u-icon>
										</view>
									</view>
								</u-col>
							</u-row>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
import classifyData from '@/common/classify.data.js';
export default {
	name: 'foodMallList',
	props: {
		mallId: {
			type: String,
			default: '1'
		}
	},
	data() {
		return {
			scrollTop: 0, //tab标题的滚动条位置
			oldScrollTop: 0,
			current: 0, // 预设当前项的值
			menuHeight: 0, // 左边菜单的高度
			menuItemHeight: 0, // 左边菜单item的高度
			itemId: '', // 栏目右边scroll-view用于滚动的id
			tabbar: [],
			detailMap: new  Map(),//存放点单的内容
			menuItemPos: [],
			arr: [],
			scrollRightTop: 0, // 右边栏目scroll-view的滚动条高度
			timer: null, // 定时器
		};
	},
	created() {
		this.getMenuData();
	},
	methods: {
		//获取列表数据
		async getMenuData() {
			let leftData = await this.getMenuLeft(this.mallId);
			for (let i = 0; i < leftData.length; i++) {
				let tempData = {};
				tempData.name = leftData[i].name;
				let detailData = await this.getMenuDetail(leftData[i].id, this.mallId);
				detailData.forEach(item => {
					item.num=0
					item.minusShow=false
					// console.log(item.name);
					// console.log(item.imgUrl);
					item.image = this.$u.http.config.baseUrl.concat(item.imgUrl);
					// console.log(item.image);
				});
				tempData.foods = detailData;
				this.tabbar.push(tempData);
			}
		},
		getMenuLeft(index) {
			return new Promise((resolve, reject) => {
				this.$u.get(`prod-api/api/takeout/category/list?sellerId=${index}`).then(res => {
					resolve(res.data);
				});
			});
		},
		getMenuDetail(categoryId, sellerId) {
			return new Promise((resolve, reject) => {
				this.$u
					.get(`/prod-api/api/takeout/product/list?categoryId=${categoryId}&sellerId=${sellerId}`, {}, {})
					.then(res => {
						resolve(res.data);
					});
			});
		},
		// 点击左边的栏目切换
		async swichMenu(index) {
			if (this.arr.length == 0) {
				await this.getMenuItemTop();
			}
			if (index == this.current) return;
			this.scrollRightTop = this.oldScrollTop;
			this.$nextTick(function() {
				this.scrollRightTop = this.arr[index];
				this.current = index;
				this.leftMenuStatus(index);
			});
		},
		// 获取一个目标元素的高度
		getElRect(elClass, dataVal) {
			new Promise((resolve, reject) => {
				const query = uni.createSelectorQuery().in(this);
				query
					.select('.' + elClass)
					.fields(
						{
							size: true
						},
						res => {
							// 如果节点尚未生成，res值为null，循环调用执行
							if (!res) {
								setTimeout(() => {
									this.getElRect(elClass);
								}, 10);
								return;
							}
							this[dataVal] = res.height;
							resolve();
						}
					)
					.exec();
			});
		},
		// 观测元素相交状态
		async observer() {
			this.tabbar.map((val, index) => {
				let observer = uni.createIntersectionObserver(this);
				// 检测右边scroll-view的id为itemxx的元素与right-box的相交状态
				// 如果跟.right-box底部相交，就动态设置左边栏目的活动状态
				observer
					.relativeTo('.right-box', {
						top: 0
					})
					.observe('#item' + index, res => {
						if (res.intersectionRatio > 0) {
							let id = res.id.substring(4);
							this.leftMenuStatus(id);
						}
					});
			});
		},
		// 设置左边菜单的滚动状态
		async leftMenuStatus(index) {
			this.current = index;
			// 如果为0，意味着尚未初始化
			if (this.menuHeight == 0 || this.menuItemHeight == 0) {
				await this.getElRect('menu-scroll-view', 'menuHeight');
				await this.getElRect('u-tab-item', 'menuItemHeight');
			}
			// 将菜单活动item垂直居中
			this.scrollTop = index * this.menuItemHeight + this.menuItemHeight / 2 - this.menuHeight / 2;
		},
		// 获取右边菜单每个item到顶部的距离
		getMenuItemTop() {
			new Promise(resolve => {
				let selectorQuery = uni.createSelectorQuery();
				selectorQuery
					.selectAll('.class-item')
					.boundingClientRect(rects => {
						// 如果节点尚未生成，rects值为[](因为用selectAll，所以返回的是数组)，循环调用执行
						if (!rects.length) {
							setTimeout(() => {
								this.getMenuItemTop();
							}, 10);
							return;
						}
						rects.forEach(rect => {
							// 这里减去rects[0].top，是因为第一项顶部可能不是贴到导航栏(比如有个搜索框的情况)
							this.arr.push(rect.top - rects[0].top);
							resolve();
						});
					})
					.exec();
			});
		},
		// 右边菜单滚动
		async rightScroll(e) {
			this.oldScrollTop = e.detail.scrollTop;
			if (this.arr.length == 0) {
				await this.getMenuItemTop();
			}
			if (this.timer) return;
			if (!this.menuHeight) {
				await this.getElRect('menu-scroll-view', 'menuHeight');
			}
			setTimeout(() => {
				// 节流
				this.timer = null;
				// scrollHeight为右边菜单垂直中点位置
				let scrollHeight = e.detail.scrollTop + this.menuHeight / 2;
				for (let i = 0; i < this.arr.length; i++) {
					let height1 = this.arr[i];
					let height2 = this.arr[i + 1];
					// 如果不存在height2，意味着数据循环已经到了最后一个，设置左边菜单为最后一项即可
					if (!height2 || (scrollHeight >= height1 && scrollHeight < height2)) {
						this.leftMenuStatus(i);
						return;
					}
				}
			}, 10);
		},
		minusClick:function(item){
			console.log(item.id)
			if(item.num!=0){
				--item.num
			}
			let money= item.price*item.num
			let data ={}
			data.num=item.num
			data.money= money
			this.$emit("getShopData",item.id,data)
			console.log(item.name)
		},
		plusClick:function(item){
			++item.num
			item.minusShow=true
			let money= item.price*item.num
			let data ={}
			data.num=item.num
			data.money= money
			this.$emit("getShopData",item.id,data)
		}
	}
};
</script>

<style lang="scss" scoped>
.u-wrap {
	height: calc(100vh);
	/* #ifdef H5 */
	height: calc(100vh - var(--window-top));
	/* #endif */
	display: flex;
	flex-direction: column;
}

.u-search-box {
	padding: 18rpx 30rpx;
}

.u-menu-wrap {
	flex: 1;
	display: flex;
	overflow: hidden;
}

.u-search-inner {
	background-color: rgb(234, 234, 234);
	border-radius: 100rpx;
	display: flex;
	align-items: center;
	padding: 10rpx 16rpx;
}

.u-search-text {
	font-size: 26rpx;
	color: $u-tips-color;
	margin-left: 10rpx;
}

.u-tab-view {
	width: 200rpx;
	height: 100%;
}

.u-tab-item {
	height: 110rpx;
	background: #f6f6f6;
	box-sizing: border-box;
	display: flex;
	align-items: center;
	justify-content: center;
	font-size: 26rpx;
	color: #444;
	font-weight: 400;
	line-height: 1;
}

.u-tab-item-active {
	position: relative;
	color: #000;
	font-size: 30rpx;
	font-weight: 600;
	background: #fff;
}

.u-tab-item-active::before {
	content: '';
	position: absolute;
	border-left: 4px solid $u-type-primary;
	height: 32rpx;
	left: 0;
	top: 39rpx;
}

.u-tab-view {
	height: 100%;
}

.right-box {
	background-color: rgb(250, 250, 250);
}

.page-view {
	padding: 16rpx;
}

.class-item {
	margin-bottom: 30rpx;
	background-color: #fff;
	padding: 16rpx;
	border-radius: 8rpx;
}

.class-item:last-child {
	min-height: 100vh;
}

.item-title {
	font-size: 26rpx;
	color: $u-main-color;
	font-weight: bold;
}

.item-menu-name {
	font-weight: normal;
	font-size: 24rpx;
	color: $u-main-color;
}

.item-container {
	display: flex;
	flex-wrap: wrap;
}

.thumb-box {
	width: 33.333333%;
	display: flex;
	align-items: center;
	justify-content: center;
	flex-direction: column;
	margin-top: 20rpx;
}

.item-menu-image {
	width: 120rpx;
	height: 120rpx;
}
.myCartNumber {
	display: flex;
	display: -webkit-flex;
	flex-direction: row;
	justify-content: center;
	align-items: center;
}
</style>
</style>
